The present invention relates to an apparatus for preparing a beverage using a soluble preparation, comprising a container for the soluble preparation, a mixer provided with a mixing chamber, said chamber having a filling inlet for the soluble preparation, at least one opening for supplying a liquid for solubilizing the preparation and forming the beverage, a duct for evacuating any vapour and/or aerosol which forms during preparation of the beverage, said duct comprising a suction fan, as well as an opening for dispensing the prepared beverage, a centrifuging device housed inside said mixing chamber and rotationally operated by an associated electric motor positioned outside said chamber, means for conveying a predetermined quantity of soluble preparation from the said container to the filling inlet of said mixing chamber, as well as means for conveying the solubilization liquid from the associated source to the respective opening of the mixing chamber. An apparatus of the type mentioned above is known from the art in the sector and is, for example, described in Italian published patent application IT VR.2004A000124, in GB patent No. 1,004.814 and in German published patent application DE 33 42 157.
As is known, during formation of the reconstituted beverage from soluble preparations, remixing of the quantity of preparation with the solubilization liquid which, in most cases, is water from a source at a suitable pressure and temperature, produces a certain evaporation of the water and the formation of aerosol.
The fine water spray and vapour produced by the centrifuging member pass out of the mixing chamber and, via the soluble-preparation filling inlet, permeate the container holding the preparation and the components for feeding the latter, greatly increasing the local moisture level.
The continuous alternation of vapour flows during dispensing and drying flows during the pauses in operation of the apparatus has the effect that part of the soluble preparation is transformed, firstly into a sticky mass, and then into a hard crust which prevents proper flowing of the preparation until blockage of the feeding means occurs, especially when these means are in the form of feeder screw or Archimedes' screw, as is conventionally used in the known art.
In order to overcome this drawback, the known art, as described in the cited prior art documents, envisages the insertion of a fan inside the vapour evacuation duct and, in case of IT VR2004A000124, also the operation of the fan by means of the same motor which causes rotation of the centrifuging member positioned inside the mixing chamber.
Although these known solutions allow aspiration of the vapour produced during formation of the beverage and conveying thereof far from the filling inlet of the mixing chamber, it nevertheless has the drawback that it operates during formation of the beverage when, inside the mixing chamber, the specific volatile aromatic and flavouring molecules of the beverage being prepared are also released and consequently removed from the beverage, adversely affecting the aroma and taste thereof.
The abovementioned drawback cannot be entirely eliminated even if, in accordance with another solution which is also known, the fan installed in the vapour evacuation duct is operated by means of a motor which is separate from that of the centrifuging member and which can therefore be operated after the beverage has been formed and dispensed, nor if the mixing chamber filling inlet is provided with suitable sealed closing means operating during centrifuging of the preparations and formation of the beverage.
In this latter case, in particular, the mixing chamber is placed under a vacuum by the centrifuging device, when it is operated in order to prepare the beverage, and the vacuum which forms there tends to favour further the evaporation of the lighter and more volatile molecules and therefore especially the molecules associated with the aroma of the soluble preparation.
The problem of avoiding a deterioration of the soluble product from which the beverage, such as coffee, milk, chocolate, tea and many other beverages, is reconstituted, and, at the same time, preserving the specific aroma of the reconstituted beverage, is particularly serious in the case of those soluble preparations which are specifically produced using processing techniques intended to preserve the characteristics of the aromatic molecules of the original primary foodstuff and a major drawback could arise from dispersion of these molecules owing to an apparatus which is not suitable for conservation thereof.
It is known that the perception of the quality of a food or a beverage presupposes that, during consumption thereof, a quantity of volatile aromatic molecules in a concentration greater than the olfactory threshold is released, so that the nasal mucous is able to perceive them in the form of a perfume or aroma.